Core carrying mandrel



Mill'dl 4, 1969 w T v I 3,430,890

' com: CARRYING-MANDREL Sheet 1 of 4 Filed Aug. 7, 1967 H157 ATTORNEYS March 4, 1969 a. AQWHITEMAN CORE CARRYING MANDREL g TQ Q Sheet Z M\ \\N 3% km M g Filed Aug. 7, 1967 INVENTOR BENTON A.WHITEMAN ms ATTORNEYS March 4, 1969 A. WQ-IT MAN" 3,430,890

CORE CARRYING MANDREL Sheet Filed Aug. '2, 1967 I INVE NTOR BENTON A.WHITEMAN 410, way/4M HIS ATTORNEYS Sheet Filed Aug. 7, 1967 N A M S E. U T R I 0 H M M j M W 0 E W VN A m0 M w E H B N United States Patent O 3,430,890 CORE CARRYING MANDREL Benton A. Whiteman, Richmond, Va., assignor to Reynolds Metals Company, Richmond, Va., a corporation of Delaware Filed Aug. 7, 1967, Ser. No. 658,941

US. Cl. 24272.1 26 Claims Int. Cl. B6511 75/18 ABSTRACT OF THE DISCLOSURE CROSS-REFERENCE TO RELATED APPLICATIONS This application is related to copending patent applications, Ser. No. 475,218, filed July 27, 1965, and Ser. No. 497,069, filed Oct. 18, 1965.

BACKGROUND OF THE INVENTION During the winding of coils such as electrical coils made from an elongated strip of electrically conductive material it is generally necessary to wind such elongated strip of material on a suitable tubular core which is normally rotatably supported on an associated mandrel. The basic problem is to provide a mandrel which can be used in an automatic coil winding apparatus to pick up a tubular core from a suitable supply bin, move it to a winding station, and then radially expand against inside surface means of such tubular core to provide a stable support enabling the elongated strip to be easily wound around the tubular core. It is particularly desirable to provide a mandrel construction which is of strong structural strength, essentially foolproof in operation, economical to produce, and enables forming of coil construction of high quality.

SUMMARY This invention provides a rugged radially expandable mandrel which is of economical construction, efficient in operation, and particularly adapted to be used in association with an automatic coil winding apparatus.

Other details, advantages, and uses of this invention will become apparent as the following description of the exemplary embodiments thereof presented in the accompanying drawings proceeds.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate exemplary embodiments of this invention, in which:

FIGURE 1 is a perspective view of an exemplary strip conductor coil construction made using the improved mandrel of this invention;

FIGURE 2 is a perspective view illustrating one exemplary embodiment of a coil winding apparatus using the mandrel of this invention to form the coil construction of FIGURE 1;

FIGURE 3 is a fragmentary perspective view illustrating electrical leads attached by the apparatus of FIG- URE 2 to an elongated strip of electrically conductive material used in forming the coil construction of FIG- URE 1;

FIGURE 4 is a composite view with parts in section and parts broken away and particularly illustrating one exemplary embodiment of a radially expandable core carrying mandrel of this invention which has driven means at its terminal end adapted to engage associated drive means, with a fragmentary portion of such drive means also being shown spaced from such driven means.

FIGURE 5 is a view similar to FIGURE 4 with the driven means operatively connected to the drive means;

FIGURE 6 is a cross-sectional view on the line 66 of FIGURE 4;

FIGURE 7 is an exploded perspective view particularly showing cylindrical segments and associated parts comprising the radially expandable mandrel shown in FIGURES 4 and 5;

FIGURE 8 is a view similar to FIGURE 4, illustrating another exemplary embodiment of a radially expandable core carrying mandrel of this invention and also illustrating a fragmentary portion of an associated drive means therefor arranged in spaced relation from the driven means of such mandrel; and

FIGURE 9 is an exploded perspective view particularly illustrating compression clutch means comprising the drive means used to drive the exemplary mandrel of FIGURE 8.

DESCRIPTION OF THE ILLUSTRATED EXEMPLARY EMBODIMENTS An exemplary strip conductor coil construction or coil made by the apparatus of this invention is shown in FIG- URE 1 and indicated generally by the reference numeral 25. Coil 25 comprises a tubular and substantially right circular cylindrical core element 26 which has a ribbon or strip 27 of electrically conductive material wound thereon in a manner as will be hereinafter described. Strip 27 has inner end means comprising an inner electrical lead 30 fixed thereto and outer end means comprising an outer electrical lead 31 suitably fixed thereto. The completed coil 25 is adapted to be installed in an associated electrical system with its lead 30 and 31 suitably electrically connected in a known manner.

In many applications the housing means, or the like, provided immediately adjacent coil 25 may have a special configuration requiring that coil 25 be provided with an outer peripheral configuration corresponding to such adjacent housing means. For example, such adjacent housing means may have end portions which are substantially frusto-conical thus requiring that coil 25 have end surfaces which are tapered or frusto-conical in a corresponding manner and essentially as shown in FIGURE 1.

In the exemplary coil 25 presented in FIGURE 1 and made by the apparatus of this invention the under side of the elongated strip of conductive material 27 is preferably prelaminated to an insulative strip or coating of insulating material before the same is wound on the core element 26 to provide electrical insulation means between adjacent coils of the strip of conductive material 27. However, if desired, strip 27 can be wound on core element 26 in unison with a separate strip of insulating material so that the strip of insulating material is interleaved between adjacent coils of the strip of conductive material 27 to electrically insulate adjacent coils of strip 27 from each other.

The exemplary coil winding apparatus used in forming the strip conductor coil construction 25 of FIGURE 1 in a substantially continuous manner is generally indicated by the reference numeral 32 in FIGURE 2. Apparatus 32 includes a frame structure 33 rotatably carrying a supply roll 34 of conductive strip material 27. As previously stated, the material 27 preferably has a strip or coating 35 of insulating material laminated to its lower surface, as illustrated in FIGURE 3, to provide electrical insulation between adjoining coils.

The tubular core elements 26 may be made of cardboard or the like and are contained in a suitable hopper means or hopper 36. Hopper 36 has a downwardly extending chute 37 extending from its lower end. Each core element is adapted to be serially fed into a retainer 33 provided at the terminal lower end of chute 37 and supported to enable it to be easily picked up by an associated mandrel in a manner to be subsequently described.

As illustrated in FIGURE 2, frame structure 33 carries a rotary table 39 which is adapted to be indexed in a rotary manner about a fixed vertical axis. Table 39 carries three actuating means or actuators shown as three fiuid cylinders each designated by the numeral 40.

Each cylinder 40 has a telescoping rod 41 which carries support means enabling coil to be formed thereon and such support means comprises a radially expandable and freely rotatable mandrel 42 carried at the terminal end of telescoping rod 41. Each cylinder is adapted to extend and yieldingly hold its mandrel 42 into operative engagement with drive means therefor to be described in detail subsequently.

The table 39 is adapted to index the mandrels 42 through three stations 45, 46, and 47. When a mandrel 42 is indexed to station 45, the associated cylinder 40 extends associated rod 41 radially outwardly telescoping mandrel 42 Within a core element 26 supported within retainer 38 at the lower end of hopper 36.

When the mandrel 42 at station 45 has a core 26 thereon, the associated piston rod 41 is retracted by cylinder 40 so that the core 26 is carried by mandrel 42 out of the retainer 38 whereby such retracted mandrel can be indexed from station 45 to winding station 46. Hopper 36 contains a plurality of cores 26 which are adapted to be serially dropped into retainer 38 through chute 37 as previously mentioned. As each core 26 is removed by an associated mandrel from retainer 38 another core 26 drops in its place.

With the core carrying mandrel 42 now at station 46, the piston rod 41 thereof is extended to interconnect mandrel 42 by suitable driven clutch means 50, see FIGURE 4, provided in its terminal outer end to suitable cooperating driving clutch means 51 attached by a pin 88 to an axially telescoping and rotatable drive means or shaft 52 comprising winding apparatus 32. As drive shaft 52 is rotated, the same rotates mandrel 42 at station 46 to cause elongated strip 27 to be wound on the core 26 carried by the rotating mandrel 42 in a manner as will be hereinafter described.

After a completed strip conductor coil 25 has been formed on mandrel 42 at station 46, the associated piston rod 41 is retracted to thereby disconnect the driven mandrel 42 from drive shaft 52 and specifically to thereby move driven clutch means away from driving clutch 51, whereby the retracted mandrel 42 is then indexed from station 46 to station 47. With the completed strip conductor coil 25 on mandrel 42 at station 47, the associated piston rod 41 is extended whereby the strip conductor coil 25 is held in a position at the station 47 so that a pair of stripping members each designated by the numeral 54, see FIGURE 2, can strip the finished strip conductor coil from mandrel 42.

The stripping members 54 are pivotally mounted to a support 55 by suitable pivot pins respectively carrying pinion gears disposed in meshing relation with each other. One of the stripping members 54 is interconnected to a piston rod 56 adapted to be extended and retracted by a fluid cylinder 57 carried by support 55. Thus, with a completed strip conductor coil 25 being held at station 47 by an extended mandrel 47, cylinder 57 is actuated to telescope its rod 56 outwardly and through the action of the above mentioned pinion gears stripping members 54 are brought into clamping engagement in a known manner on opposite sides of coil 25.

With the strip conductor coil 25 now firmly clamped between the stripping members 54 retraction of the piston rod 41 of the mandrel 42 at station 47 pulls such mandrel out of the core 26 of the completed strip conductor coil 25 so that the particular mandrel 42 can be subsequently indexed to the station 45 by indexing table 39. With the mandrel 42 at station 47 now retracted from within core 26 of the completed strip conductor coil 25, the cylinder 57 can be deactuated to return the stripping members 54 to the open position illustrated in FIGURE 2 whereby such members drop the completed strip conductor coil 25 onto a chute means 58. The completed strip conductor coil 25 moves down chute 58 to a table 60 for subsequent testing, packaging, and the like of the completed strip conductor coils 25 produced by apparatus 32.

The elongated strip 27 is adapted to be fed from supply roll 34 through suitable slack reducing and tension applying roller device designated generally by the numeral 61. Thus, strip 27 passes from its free wheeling supply roll 34 around a roller 62 carried by a frame means 63 of device 61 which is pivotally mounted to the frame 33 of apparatus 32 by a pivot means 64. Strip 27 continues from roller 62 around a pair of idler rolls 65 and 66 and along a combination guide means and bearing surface means designated by the numeral 67 to winding station 46 so that edge means of the terminal end portion of strip 27 being wound is held substantially in a fixed vertical plane during winding thereof at station 46.

A rod 59 is slidably carried by frame means 63 and has a roller 69 rotatably supported at its lower end and resting on supply roll 34. An arm 79 is provided and has one end pivotally mounted to the frame 33 by pivot means 70 and its opposite end adjustably carried by rod 59. Arm 79 is interconnected to member 63 by an adjustable tension spring 68.

As supply roll 34 is continuously used, less and less spring tension by spring 68 is needed whereby the interaction of the linkages comprising device 61 together with spring 68 automatically provides the desired tension. For example, as the supply roll 34 decreases in diameter, the roller 69 carries member 59 downwardly to thereby carry the right end of arm 79 downwardly to lessen the tension of spring 68 the correct amount.

Having presented a detailed description of th apparatus and method which make possible the forming or winding of coil construction 25 illustrated in FIGURE 1, a brief general description will now be made to highlight the simplicity with which a complicated coil construction is easily made using the above described apparatus and method.

Accordingly, a mandrel 42 carrying a core 26 is indexed into position into winding station 46 in a manner as previously described. Immediately upon indexing mandrel 42 into winding station 46 it is positioned essentially as illustrated in FIGURE 4 of the drawings. Suitable control means provided at winding station 46 is actuated in a known manner so that the mandrel 42 is extended by fluid cylinder 40 from the position illustrated in FIG- URE 4 to the position illustrated in FIGURE 5 of the drawings.

As mandrel 42 is extended to the position shown in FIGURE 5, radially expandable portions provided thereon are urged radially outwardly to engage the inside surface of core 26 and thereby firmly hold such core in position to enable winding of the elongated strip 27 thereon. The detailed construction of the exemplary mandrel 42 of this invention and particularly the detailed arrangement making possible the firm gripping of core 26 to enable winding strip 27 thereon will be described in detail subsequently.

With mandrel 42 moved to the position shown in FIG- URE 5 the mechanical pressure between driven clutch face 50 and driving clutch face 51 actuates an associated switch of known constuction which in turn energizes the drive motor which drives the drive shaft 52 to start shaft 52 rotating and start the winding of strip 27 on core 26.

Suitable means is provided for initially taping the inner end of strip 27 to core 26 to start the winding action as well as taping the outer end portion of strip 27 in position in the completed coil 25 and such means together with means employed to attach electrical leads 30 and 31 to strip 27 are described in detail in the cross-referenced copending application Ser. No. 497,069.

Having described the detailed apparatus and method which makes possible the forming of coil 25 having an exemplary tapered configuration corresponding to the configuration of an associated housing means, or the lik the detailed description will now proceed with a detailed description of the exemplary radially expandable mandrel 42 comprising one embodiment of this invention which makes possible the easy pickup of a core 26 from within retainer 38 of apparatus 32, indexing of such core 26 to winding station 46, and suitably winding elongated strip conductor 27 thereon to form coil 25 in the manner previously described. Reference is now made to FIGURES 4-7 of the drawings wherein mandrel 42 is illustrated in detail.

Exemplary mandrel 42 has a freely rotatably rigid support means or construction 190 comprised of a cylindrical member 191 having a threaded outer Surface shown at 192 and a central bore 193 which extends completely therethrough and is provided with a counterbore 194 in one end thereof. Support means or assembly 190 also has a sleeve-like member 195 provided with a threaded bore 196 in one end portion thereof and threads 196 are adapted to be threaded over threads 192 of member 191 to hold members 195 and 191 together. Member 195 also has cam surface means shown as a frusto-conical cam surface 197 provided in its opposite end portion and for a purpose to be described in detail subsequently.

Assembly 190 and hence the entire mandrel 42 is supported at the terminal end portion of rod 41 which is actuated by fluid cylinder 40 and in this example of the invention bearing means shown as a pair of spaced apart ball bearings each designated by the numeral 201 are provided in counterbore 194 for holding support assembly 190 and hence the entire mandrel 42 at the terminal end of rod 41. In this manner the entire mandrel 42 is freely rotatable so that it may be readily and easily driven by driving clutch face 51 fixed at the terminal end of drive shaft 52.

The bearings 201 are suitably fastened in position at the terminal end of rod 41 in any suitable manner and preferably have a spacer 202 arranged therebetween so as to provide a broader and more stable supporting surface as defined by spaced apart inner races of bearings 201. In this example of the invention bearings 201 are fixed to rod end portion 41 by press fitting their inner races against the outside diameter rod 41 and member 191 is moved in position with cylindrical surface means defining its bore 194 engaging the outside races of bearings 201. Assembly 190 and hence mandrel 42 is prevented from being pulled off of rod 41 by an suitable means such as a split compressible ring or snap ring 203. Ring 203 is snapped into position in a cooperating groove 204 provided in member 191. Rod 41 has a bore 205 extending axially inwardly from its terminal end and terminating in a surface 209 at its inner end to thereby define a blind hole in the terminal end of rod 41.

Mandrel 42 has a rigid shaft means or construction designated by the numeral 206 which has a cylindrical terminal outer end portion which is supported within bore 193 of member 191 and a cooperating aligned bore 207 in member 195 and supporting shaft 206 extends substantially centrally through members 191 and 195.

Shaft 206 has a necked down right circular cylindrical portion 210 defining its terminal inner end and termimating in a circular surface 211. The outside diameter of cylindrical portion 210 is adapted to be easily inserted within bore 205 provided in the end portion of rod 41 so that cylindrical portion 210 is readily axially slidable along bore 205.

Shaft 206 has elongated slot means 212 extending therethrough substantially transverse to and along its longitudinal axis. Slot means or slot 212 has side surface means defining a controlled width and end surface means each designated by the numeral 212A defining a predetermined length for slot 212 whereby slot 212 is substantially rectangular in outline while extending diametrical- 1y across shaft 206. Slit 212 is adapted to allow movement of shaft 206 relative to member 195 and hence assembly in a manner as will be presently described.

Member 191 has a passage 213 extending substantially diametrically thereacross and passage or bore 213 is adapted to receive a cooperating pin 214. Pin 214 has a thickness or diameter corresponding to the above mentioned controlled width of slot 212, i.e. the diameter of pin 214 is slightly smaller than the controlled width of slot 212.

With this construction it is seen that supporting shaft 206 is supported centrally along support assembly 190 and its rectangular slot 212 is aligned with cylindrical bore 213. Having thus aligned shaft 212 with respect to bore 213 pin 214 is then inserted in position to thereby provide coupling means coupling shaft 206 for simultaneous rotation with member 191 and hence support assembly 190 while allowing limited axial movement of shaft 206 relative to assembly 190. Shaft 206 is limited by end surface means 212A in its axial movement so that shaft 206 cannot be moved except for a limited distance on either side of pin 214.

With pin 214 installed in position through cylindrical opening 213 and through rectangular slot 212 of shaft 206, sleeve portion 195 is then threaded in position around shaft 206 so that its bore 207 provides a bearing surface for the outer portion of shaft 206 in a similar manner as bore 193 provides a supporting surface for the inner portion of shaft 206.

Urging means shown as an urging spring 216 is provided in mandrel 42 and such spring is carried within bore 205 so that it acts between surface 209 provided in rod 41 and surface 211 defining the terminal end of cylindrical end portion 210 of shaft 206. Spring 216 normally yieldingly urges shaft 206 to the left as viewed in FIG- URE 4 of the drawings for reasons to be explained in detail hereinafter.

Support shaft 206 has a threaded terminal outer end as shown at 217 and driven clutch face 50 has a cooperating threaded bore 215 enabling it to be threaded in position at the terminal end of shaft 206 and suitably fixed in position as by a set screw 213. A guide bore 219 is also provided in the terminal end of shaft 206 which is adapted to guide a suitable guide pin 220 fixed at the outer end of shaft 52. Pin 220 and guide bore 219 cooperate to assure clutch faces 50 and 51 are properly intermeshed once mandrel 42 is telescoped outwardly so that its clutch face 50 engages clutch face 51.

Mandrel 42 also has a collar 221 provided with a central threaded opening 222 enabling collar 221 to be threaded axially along threads 217 of shaft 206. Collar 221 has cooperating cam surface means shown as a frustoconical cam surface 223 which cooperates with frustoconical cam surface 197 to provide a camming action for radially expandable means, to be presently described, supported between cam surfaces 197 and 223.

Mandrel 42 has holding means for holding core 26 and hence coils 25 on mandrel 42 and such holding means comprise a plurality of radially expandable cylindrical sectors three of which have been designated by the same numeral 224, see FIGURE 7, and a fourth one of which has been designated by the numeral 225. Cylindrical sectors 224 and 225 are identical with the exception that sector 225 has means for initially retaining a tubular core 26 on mandrel 42 to enable Withdrawal of core 26 from associated retainer 38 of apparatus 32 and indexing thereof into winding position at station 46. Therefore, the detailed description will now proceed describing only those features which are common to all sectors 224 and 225.

7 The detailed description of sector 225 will be made subsequently.

Cylindrical sectors 224 and 225 are constructed so that in their collapsed condition and with such sectors being held together against shaft 206 they cooperate to define a substantially cylindrical opening designated by the numeral 226. Sectors 224 and 225 are held against shaft 206 by suitable yielding means which in this ex ample of the invention comprise a pair of spaced apart O-rings each designated by the numeral 230 and each being stretchable and made of a material which once the stretching force is released will return sectors 224 and 225 against support shaft 206.

Each sector 224 and 225 has substantially frustoconical surface means at its opposite ends designated by the numerals 231 and 232 respectively. With the cylindrical sectors 224 and 225 held by O-rings 230 against shaft 206 it will be seen that frusto-conical surface means 231 is aligned to cooperate with frusto-conical surface means 223 of collar 221 while frusto-conical surface means 232 is adapted to cooperate with frusto-conicnl surface means 197 provided in member 195.

Suitable means may be provided in association with one or more of the cylindrical sectors of mandrel 42 to prevent rotation of such sectors relative to shaft 206 as shaft 206 is rotated. In this example of the invention suitable key means shown as a key 234 is provided for association with each cylindrical sector. Each key 234 is received in a cooperating groove 235 in each associated cylindrical sector as well as in a cooperating groove 236 provided in collar 221. Thus, it is seen that cylindrical sectors 224 and 225 are yieldingly held by O-rings 230 against shaft 206 and are prevented from rotating with respect to shaft 206 by keys 234.

With mandrel 42 in its unclutched condition, shown in FIGURE 4, the yielding means or O-rings 230 cooperate with spring 216 to push shaft 206 to the left and keep cylindrical sectors collapsed against shaft 206. However, upon urging shaft 206 to the right, as will be presently described, the cam surfaces 197, 223, 23,1, and 232 cause cylindrical sectors 224 and 225 to be urged radially outwardly wtih respect to support shaft 206 to engage and firmly hold core 26.

As mandrel 42 is urged to the left from the position of FIGURE 4 to the position of FIGURE 5 by fluid cylinder 40, in the manner previously described, driven clutch face 50 is urged into engagement with driving clutch face 51 at the terminal end of driving shaft 52. Support shaft 206 is thus urged to the right relative to support assembly 190, such relative movement being allowed by slot 212 causing cylindrical sectors 224 and 225 to be urged radially outwardly. This causes the outside diameter of such cylindrical sectors to be firmly urged against the inside surface of tubular core 26 and thereby hold core 26 firmly in position to enable winding of an elongated strip 27 therearound. Upon rotating mandrel 42 with drive shaft 52, through coupled clutch faces 50 and 51, it will be seen that the mandrel 42 is driven so that it freely rotates about its roller bearings 201.

The fiuid cylinder 40 comprising apparatus 32 is of a known type which holds its rod end 41 extended outwardly with a given yieldable force. However, known construction cylinder 40 may be overridden while it continues to exert a substantially constant force against its rod end 41.

The winding of strip 27 is commenced as previously described and as it continues suitable cam means may be provided as a part of apparatus 32 to urge end portion 52 to the right as viewed in FIGURE 5 and in a controlled manner. This urging action is in turn transmitted through assembly 190 to rod end 41 to override cylinder 40. The cam means mentioned above may thus be utilized with mandrel 42 and cylinder 40 to provide the coil with any desired configuration such as the frustoconical end surfaces illustrated in FIGURE 1.

As previously indicated, cylindrical sector 225 is different from the other sectors 224 and its main difference is that sector 225 supports a core retaining means shown as a plunger or retainer 240. Cylindrical sector 225 has a cutout shown at 242 which is adapted to receive retainer 240 therein. Retainer 240 has a central opening 243 provided therein which is adapted to receive a compression spring 244. Spring 244 acts between sector 225 and surface means defining the inner portion of opening 243 to thereby urge retainer 240 outwardly away from sector 225.

Retainer 240 also has a pair of legs each designated by the numeral 247 etxending from its opposite ends and dimensioned so as to extend beyond O-rings 230. Thus, as seen particularly in FIGURE 4 of the drawings, spring 244 urges retainer 240 radially outwardly so that its top surface extends above the outer surface of cylindrical sector 225.

The structural arrangement and height of retainer 240 is such that it is urged by spring 244 so that its leg portions 247 are urged against O-rings 230 to limit the outward movement thereof. However, upon inserting mandrel 42 within an associated tubular core 26 the retainer 240 is urged by spring 244 to initially retain core 26 on the mandrel 42. To enable easier insertion of mandrel 42 within an associated tubular core 26 retainer 240 has a chamfered or inclined forward end as shown at 250.

Thus, it is seen that mandrel 42 of this invention is of rugged construction and is supported for free rotation in a cantilevered manner at the terminal end of rod 41. Further, the radially expandable segments 224 and 225 comprising mandrel 42 provide a firm gripping or holding action along the entire elongated surface of inside surface means defining core 26. The construction of mandrel 42 makes it possible to use this type of expanding mandrel not only in coil winding operations but also in other applications where an expandable mandrel is required irrespective of whether it is necessary to rotatably support large heavy loads or comparatively small light ones.

Mandrel 42 also has shoulder means to limit the inward movement or travel of a tubular core as it is axially moved in position on such mandrel. In this example of the invention the shoulder means is comprised of a shoulder 252 provided on the terminal inner end of each cylindrical sector 224 and 225. Each shoulder 252 has transverse surface means shown as a transverse surface 253 which is arranged substantially perpendicular to its associated cylindrical sector and provides the surface against which the terminal inner end of a tubular core to be carried by mandrel 42 is adapted to engage.

Another exemplary embodiment of this invention is illustrated in FIGURES 8 and 9 of the drawings. The mandrel, as illustrated in FIGURES 8 and 9, is similar to mandrel 42; therefore, such mandrel will be designated generally by the numeral 42A. Mandrel 42A is adapted to be used interchangeably with mandrel 42 in apparatus 32 and has a driven clutch means 50A at its terminal outer unsupported end which is adapted to be driven by a suitable cooperating driving clutch means 51A comprising the terminal outer end portion of a compression clutch means designated generally by the numeral 260A which is suitably fixed to the terminal outer end portion of shaft 52. Thus, in using mandrel 42A on apparatus 32, mandrel 42A is fastened in position in a cantilevered manner at the erminal end of rod portion 4.1 and compression clutch means or compression clutch 260A is suitably installed in position instead of the driving clutch face means 51 used in association with mandrel 42.

The description will now proceed with a detailed description of mandrel 42A and parts of mandrel 42A which are substantially identical to corresponding parts of mandrel 42 will be designated by the same numeral as in mandrel 42, also followed by the letter designation A and not described again. Only those component parts which are substantially different from corresponding parts in mandrel 42 will be designated by a new numeral also followed by the letter designation A and described in detail.

Exemplary mandrel 42A also has a freely rotatable rigid support means or assembly designated by the numeral 262A and comprised of an outer cylindrical member 263A and an inner cylindrical member 264A. Member 263A has a central bore 265A extending axially therethrough and is provided with a counterbore 266A adjacent its inner end, adjacent actuator 40.

Member 263A also has internal threads shown at 270A provided therein and comprising the terminal outer end portion of bore 265A.

Member 264A has threads 271A provided on its outside surface which are adapted to be threaded along internal threads 270A to adjustably axially position member 264A relative to member 263A. Member 264A also has a smooth central bore 273A which is adapted to slidably support a rigid shaft means or construction 275A for axial sliding movement therealong.

Support assembly 262A and thus the entire mandrel 42A is supported at the terminal end portion of rod end 41 of actuator 40 by a pair of axially spaced apart ball bearings 201A provided in counterbore 266A whereby the entire mandrel 42A is freely rotatable as it is supported in a cantilevered manner on the terminal end of rod 41.

In a manner as previously described, the bearings 201A are fastened in position at the terminal end of rod 41 in any suitable manner and preferably have a spacer 202A arranged therebetween to provide a broad and more stable supporting surface as defined by the spaced apart inner races of bearings 201A. In this exemplary embodiment of the invention bearings 201A are fixed to rod end portion 41 by press fitting their inner races against the outside diameter of rod 41 and member 263A is moved in position so that its cylindrical counterbore 266A engages the outer races of the ball bearings 201A. A snap ring 203A is snapped into position in a cooperating groove 204A pro vided in member 263A.

The rod end 41 has a bore 205 extending axially inwardly from its terminal end and terminating in a surface 209 which is adapted to receive a substantially right circular cylindrical end portion 276A of shaft 275A therewithin, so that end portion 276A is readily axially slidable within cylindrical bore 205.

In this exemplary embodiment of the invention member 263A comprising support means 262A has elongated slot means extending therethrough and designated by the numeral 280A. Slot means or slot 280A has side surface means defining a controlled width and end or stop surface means at its opposite ends each designated by the numeral 281A defining a predetermined length for slot 280A. As will be apparent from FIGURE 8 of the drawings, slot 280A extends substantially diametrically through member 263A.

Shaft 275A has an opening 282A extending substantially diametrically therethrough which is adapted to receive a cooperating pin means shown as a pin 283A. Pin 283A is suitably fixed in position through Opening 282A as by press fitting, or the like, and is arranged so that it extends through slot 280A provided in the support means 262A. Thus, the cooperating slot 280A and pin 283A comprising mandrel 42A provide a similar function as the slot means 212 and cooperating pin 214 of mandrel 42.

The diameter of pin 283A corresponds to the controlled width of slot 280A so that with axial movement of the shaft 275A within support assembly 262A the terminal outer ends move freely along the rectangular slot 280A; however, the width of slot 280A is such that relative rotary movement between the pin 283A together with its shaft 275A and support means 262A is prevented. Thus, it is seen that the rectangular slot means 280A and cooperating pin 283A provide coupling means for coupling the shaft 275A and support assembly 262A for simultaneous rotation while allowing limited axial movement of the shaft 275A with respect to the support assembly 262A.

Mandrel 42A has holding means which are yieldingly held against shaft 275A and adapted to be moved radially outwardly against inside surface means of a core to be carried on mandrel 42A in a similar manner as described in connection with mandrel 42. The holding means in this exemplary embodiment of the invention comprises a plurality of substantially cylindrical segments which are very similar to cylindrical segments 224 of mandrel 42; therefore, will be designated by numeral 224A. Cylindrical segments 224A are yieldingly held against shaft 275A by yielding means shown as stretchable O-rings 230A which are made of a rubber-like material. The rings 230A cooperate to return cylindrical segments or sectors 224A against support shaft 275A once the stretching force is released.

Each sector 224 provided on mandrel 42 of the previous embodiment has cam surface means shown as substantially frustoconical surface means 231 provided atone end thereof; however, each cylindrical sector 224A has frustoconical cam surface means 231A provided at both ends. Further, each frustoconical cam surface means 231A provided in each member 224A has groove 235A extending therealong which is adapted to receive a cooperating key 234A to prevent relative rotation between the cylindrical sectors 224A with respect to an associated cooperating cam surface means provided on mandrel 42A.

The cam surface means for moving the cylindrical sectors 224A radially outwardly with respect to shaft 275A comprise first inclined surface means shown on a ring 285A provided adjacent the inner end portion of shaft 275A and hence adjacent the inner end portion of cylindrical sectors 224A. The ring 285A has first inclined cam surface means 286A and a plurality of grooves each designated by the numeral 287A extending along cam surface means 286A. Each groove 287A is adapted to cooperate with an associated groove 235A to support an associated key 234A. It will also be noted that the ring 285A is axially slidable along shaft 275A.

Mandrel 42A also has cam surface means provided adjacent the outer end portion of shaft 275A and such cam surface means comprises a cam ring 290A which is threaded on threads 291A provided on the outer end portion of shaft 275A. Cam ring 290A has second inclined cam surface means designated by the numeral 292A and the ring 290A and hence inclined surface means 292A are supported on shaft 27 5A adjacent the outer end portion of cylindrical sectors 224A.

The ring 290A has grooves extending axially along its inclined surface means 292A and such grooves are designated by the numeral 293A and are similar to grooves 287A provided in ring 285A. Each groove 293A is adapted to cooperate with an associated groove 235A provided in a cylindrical sector 224A to receive an associated key 234A therewithin in a similar manner as described in connection with ring 285A.

As described in connection with cylindrical sectors 224 of mandrel 42, each sector 224A also has a shoulder 252A provided at its terminal inner end to limit the total inward movement of an associated core to be positioned on mandrel 42A. Each shoulder 252A also has a perpendicular surface 253A adapted to be engaged by the inner edge of an associated core.

Mandrel 42A also has an adjusting nut 296A which serves as a lock nut for locking member 264A at any desired axial position with respect to member 263A. The nut 296A enables member 264A to be axially slidably adjusted so that cam ring 285A may be axially positioned in any desired manner.

As previously indicated, cam ring 290A is adapted to be threaded along threaded portion 291A of shaft 275A. Another adjusting nut designated by the numeral 297A is adapted to be threaded along threaded portion 291A 1 1 and to serve as a jam or lock nut against ring 290A. Adjusting nut 297A has a threaded set screw or the like designated by the numeral 298A adapted to firmly secure adjusting nut 297A in any position, as desired.

Thus, it is seen that with the provision of adjusting nuts 296A and 297A the position of cam rings 285A and 290A may be precisely controlled along shaft 275A so that cores to be carried on mandrel 42A having different inside diameters may be readily accommodated. In addition, this adjustability enables the provision of an immediate effective movement, i.e., immediate radial outward movement, in response to an axial movement of shaft 275A.

Mandrel 42A also has urging means, shown as an urging spring 216A which is carried within bore 205 of rod 41 and acts between surface 209 provided in rod 41 and a surface 302A defining the terminal end of cylindrical portion 276A of shaft 275A. Spring 216A cooperates with the yielding means of resilient rings 230A to maintain the cylindrical sectors 224A collapsed against shaft 275A with the mandrel 42A in an unclutched condition.

The driven means provided at the terminal outer end of shaft 275A comprises a driven shaft portion or driven clutch means 50A, as shown at 303A. In this example of the invention the driven clutch means comprises a shaft portion of substantially rectangular cross-sectional outline.

Mandrel 42A is driven by compression clutch means designated by the numeral 260A as previously mentioned. Compression clutch means 260A comprises a main housing 305A having a cylindrical bore 306A extending through a portion thereof which is adapted to receive the terminal end of shaft 52 therewithin. Housing 305A is fixed to shaft 52 in any suitable manner. The main body portion 305A also has an outward substantially right circular cylindrical extension 307A defining its outer end. Extension 307A has a reduced diameter and has a diametral opening 310A extending therethrough which is adapted to receive a pin 311A which is held in position on extension 307A by a threaded set screw 319A threaded axially along an associated threaded opening provided in the terminal end portion of shaft portion 307A.

Compression clutch 260A also has a telescoping collet chuck or sleeve 312A of substantially tubular configuration which has a bore in its inner end portion designated by the numeral 313A and which is adapted to receive end portion 307A therewithin to support sleeve 312A for axial sliding movement. Sleeve 312A also has a transverse slot 314A provided adjacent its terminal outer end. The slot 314A is adapted to receive pin 311A therethrough so that, with sleeve 312A installed in position around extension 307A, the slot 314A enables a limited or controlled movement of the telescoping sleeve 312A with respect to the housing portion 305A.

The telescoping collet chuck 312A is adapted to be urged outwardly by a compression spring 315A which acts between a surface 316A provided on main body portion 305A and the inside surface means 317A provided on the telescoping collet chuck 312A. The compression spring 315A continuously yielding urges the telescoping collet chuck 312A outwardly.

The collet chuck 312A has a non-circular axial bore provided in its outer end portion and shown in this example of the invention as driving clutch means 51A similar in function to clutch means 51. The clutch means 51A is a rectangular outline corresponding to the noncircular rectangular outline of driven clutch means 50A.

Upon extending mandrel 42A into position by actuating actuator 40 during the winding of a coil construction driven clutch means 50A is urged against driving clutch means 51A yieldingly compressing spring 315A. As the shaft 52 is rotated, thereby rotating collet chuck 312A, the driving clutch 51A falls into clutch engagement around the driven clutch 50A by the action of spring 315A once the rectangular shaft portion of driven clutch 50A and the mating opening 51A are in alignment, whereby the mandrel 42A is rotated in a similar manner as described for mandrel 42.

The exemplary mandrel 42A is not provided with core retaining means or a plunger similar to retainer 240 of manrel 42. However, it will be appreciated that such a retainer and its associated structure could be readily provided on mandrel 42A in essentially the manner as shown and described in connection with mandrel 42.

Thus, it is see that the mandrel 42, and mandrel 42A, provide unique means for holding a core in position for the winding of a strip conductor coil or the like.

The mandrel 42A is also adapted to utilize an electromechanical switch of known construction which may be utilized to start the drive motor which rotates the shaft 52 and in a similar manner as previously mentioned in connection with a similar switch provided for the mandrel 42. Thus, once the mandrel 42A is actuated into position by actuator 40 against the compression clutch 260A the electromechanical switch 180 is energized to start the coil winding operation.

Terms such as ends, inner, outer, left, right, and the like, have been used in this disclosure of the invention for ease of description and merely to describe the various arrangements of component parts and their operation as illustrated in the drawings and the use of terms such as these should not be considered as limiting the scope of this invention in any way.

Thus, it is seen that an improved core carrying mandrel has been provided by this invention which is of simple, economical, and durable construction.

While present exemplary embodiments of this invention have been illustrated and described, it will be recognized that this invention may be otherwise variously embodied and practiced within the scope of the following claims.

What is claimed is:

1. A radially expandable mandrel for rotatably supporting a workpiece having inside surface means defining mandrel receiving opening means, said mandrel comprising, a rigid support means supporting said mandrel in a cantilevered manner on a supporting structure while allowing free rotation thereof, a rigid shaft means carried by said support means and having driven means fixed to its terminal end for operative engagement with cooperating drive means, coupling means coupling said shaft means and said support means for simultaneous rotation while allowing limited axial movement of said shaft means relative to said support means, holding means yieldingly held against said shaft means and adapted to be moved radially outwardly against said inside surface means, and cam means for moving said holding means radially outwardly said coupling means enabling relative axial movement of said shaft means toward said support means upon engaging said driven means against said drive means which causes said cam means to provide a radial movement of said holding means against said inside surface means to firmly hold said workpiece for rotation with said mandrel.

2. A mandrel as set forth in claim 1 further comprising yielding means yieldingly holding said holding means against said shaft means.

3. A mandrel as set forth in claim 1 in which said holding means comprises retaining means for initially retaining said workpiece in position piror to full holding engagement by said holding means.

4. A mandrel as set forth in claim 1 in which said holding means comprises a plurality of cylindrical segments and said mandrel further comprising yielding means yieldingly holding said cylindrical segments against said shaft means and urging means acting between said supporting structure and said shaft means, said urging means cooperating with said yielding means to keep said cylindrical segments collapsed against said shaft means.

5. A mandrel as set forth in claim 4 in which each of said cylindrical segments has groove means provided therein and adapted to be aligned with cooperating groove means of an adjacent cylindrical segment to define a substantially continuous annular groove means extending around said cylindrical segments, and said yielding means comprises resilient ring means nested in said annular groove means yieldingly moving said cylindrical segments radially inwardly against said shaft means.

6. A mandrel as set forth in claim 1 in which said cam means comprises, first inclined cam surface means provided adjacent the inner end portion of said shaft means and second inclined cam surface means provided adjacent the outer end portion of said shaft means, said first and second cam surface means being inclined in opposite directions, and each of said first and second cam surface means being supported by an associated rigid means and arranged immediately adjacent an associated end surface means of said holding means and with said axial movement of said shaft means said first and second cam surface means are moved closer together causing said end surface means to move along said ca-m surface means to provide said radial movement.

7. A mandrel as set forth in claim 1 in which said cam means comprises, first inclined cam surface means on said support means and second inclined cam surface means fixed on the outer end portion of said shaft means in spaced apart relation from said first cam surface means, said first and second cam surface means being inclined in opposite directions, and each of said first and second cam surface means being arranged immediately adjacent an associated end surface means of said holding means and with said axial movement of said shaft means said first and second cam means are moved closer together causing said end surface means to move along said cam surface means to provide said radial movement.

8. A mandrel as set forth in claim 1 in which said cam means comprises, first inclined cam surface means supported for axial sliding movement along the inner end portion of said shaft means, and second inclined cam surface means supported on the outer end portion of said shaft means, said first and second cam surface means being inclined in opposite directions, and each of said first and second cam surface means being arranged and adjustably positioned immediately adjacent an associated end surface means of said holding means and with said axial movement of said shaft means first and second cam means are moved closer together causing said end surface means to move along said cam surface means to provide said radial movement.

9. A mandrel as set forth in claim 6 in which said coupling means comprises, elongated slot means extending through one of said rigid means substantially trans verse to and along its longitudinal axis, said slot means being of substantially rectangular outline and defined by oppositely arranged side surface means defining a controlled width and oppositely arranged stop surface means defining a predetermined length therefor, and pin means fixed to the other of said rigid means and extending through said slot means, said pin means having a thickness corresponding to said controlled width to thereby couple said rigid means to enable said simultaneous rotation and said pin means engaging said stop surface means to provide said limited axial movement.

10. A mandrel as set forth in claim 7 in which said shaft means has a threaded outer end portion and said mandrel further comprising collar means having threaded opening means adapted to be adjustably threaded along said shaft means and fixed thereto, said first cam surface means comprises a frusto-conical cam surface on said support means, and said second cam surface means comprises a frusto-conical cam surface on said collar means.

11. A mandrel as set forth in claim 9 in which said holding means comprises a plurality of cylindrical segments and Said mandrel further comprising yielding means yieldingly holding said cylindrical segments against said shaft means and urging means acting between said support structure and said shaft means, said urging means cooperating with said yielding means to keep said cylindrical segments collapsed against said shaft means.

12. A mandrel as set forth in claim 11 further comprising key means acting between at least one of said cam surface means and its associated cylindrical segments to rotatably couple said cylindrical segments to said shaft means for simultaneous rotation therewith and as said shaft means is relatively moved axially toward said support means said first and second cam surface means are moved toward each other to engage and cam said cylindrical segments to provide said radial move ment thereof.

13. A mandrel as set forth in claim 12 in which said driven means comprises a driven shaft of noncircular cross section, said driven shaft comprising the terminal outer end of said shaft means and is adapted to be driven by compression clutch means comprising said drive means.

14. In combination: drive means, a radially expandable core carrying mandrel having driven means, and actuating means for supporting and moving said driven means of said mandrel into operative engagement with said drive means, said mandrel comprising, a rigid support means supporting said mandrel in a cantilevered manner on said actuating means, a rigid shaft means carried by said support means and having said driven means provided on its terminal outer end for operative engagement with said drive means, coupling means coupling said shaft means and said support means for simultaneous rotation while allowing limited axial movement of said shaft means relative to said support means, holding means yieldingly held against said shaft means and adapted to be moved radially outwardly against inside surface means of said core, and cam means for moving said holding means radially outwardly against inside surface means of said core, said coupling means enabling relative axial movement of said shaft means toward said support means upon actuating said actuating means and moving said driven means into operative engagement with drive means which causes said cam means to provide a radial movement of said holding means against said inside surface means of said core to firmly hold said core for rotation with said mandrel.

15. The combination as set forth in claim 14 in which said actuating means comprises rod means, said support means supports said mandrel at the terminal outer end of said rod means in said contilevered manner, and said combination further comprises urging means acting between said rod means and said shaft means to continuously urge said shaft means away from said rod means.

16. The combination as set forth in claim 15 in which said holding means comprises a plurality of cylindrical segments and said mandrel further comprises yielding means yieldingly holding said cylindrical segments aganst said shaft means, said yielding means cooperating with said urging means to keep said cylindrical segments collapsed against said shaft means.

17. The combination as set forth in claim 16 in which each of said cylindrical segments has groove means provided therein and adapted to be aligned with cooperating groove means of an adjacent cylindrical segment to define a substantially continuous annular groove means extending around said cylindrical segments, and said yielding means comprises resilient ring means nested in said annular groove means yieldingly moving said cylindrical segments radally inwardly against said shaft means.

18. The combination as set forth in claim 17 in which said resilient ring means comprises a pair of resilient rings and said mandrel further comprises retaining means for initially retaining said core in position prior to full engagement by said cylindrical segments, said retaining means comprising a core engaging member supported for radial movement within cavity means provided in a cylindrical segment, and spring means yieldingly urging said retaining means outwardly against said resilient rings so that core engaging surface means thereof extends beyond the outer periphery of its associated cylindrical segment, said pair of resilient rings holding said retaining means attached to said mandrel.

19. The combination as set forth in claim 17 in which said cam means comprises, first inclined cam surface means on said support means, second inclined cam surface means fixed on the outer end portion of said shaft means in spaced apart relation from said first cam surface means, said first and second cam surface means being inclined in opposite directions, and each of said first and second cam surface means being arranged immediately adjacent an associated end surface means of each of said cylindrical segments so that with said axial movement of said shaft means inwardly toward said support means said first and second cam surface means are moved closer together causing said end surface means to move along said cam surface means and provide said radial movement of said cylindrical segments.

20. The combination as set forth in claim 17 in which said cam means comprises, first inclined cam surface means supported for axial sliding movement along the inner end portion of said shaft means and second inclined cam surface means supported on the outer end portion of said shaft means, said first and second cam surface means being inclined in opposite directions, and each of said first and second cam surface means being arranged and adjustably positioned immediately adjacent an associated end surface means of each of said cylindrical segments so that with said axial movement of said shaft means inwardly toward said support means said first and second cam surface means are moved closer together causing said end surface means to move along said cam surface means and provide said radial movement of said cylindrical segments.

21. The combination as set forth in claim 17 in which said cam means comprises, first inclined cam surface means provided adjacent the inner end portion of said shaft means and second inclined cam surface means provided adjacent the outer end portion of said shaft means, said first and second cam surface means being inclined in opposite directions, and each of said first and second cam surface means being supported by an associated rigid means and arranged immediately adjacent an associated end surface means of each of said cylindrical segments so that with said axial movement of said shaft means inwardly toward said support means said first and second cam surface means are moved closer together causing said end surface means to move along said cam surface means and provide said radial movement of said cylindrical segments.

22. The combination as set forth in claim 21 in which said coupling means comprises, elongated slot means extending through one of said rigid means substantially transverse to and along its longitudinal axis, said slot means being of substantially rectangular outline and defined by oppositely arranged side surface means defining a controlled width and oppositely arranged stop surface means defining a predetermined length therefor, and pin means fixed to the other of said rigid means and extending through said slot means, said pin means having a thickness corresponding to said controlled width to thereby couple said rigid means to enable said simultaneous rotation and said pin means engaging said stop surface means to provide said limited axial movement.

23. The combination as set forth in claim 19 in which, said shaft means has a threaded outer end portion, said mandrel further comprises collar means having threaded opening means adapted to be adjustably threaded along said shaft means and fixed thereto, said first cam surface means comprises a frusto-conical cam surface on said support means, and said second cam surface means comprises a frusto-conical cam surface on said collar means.

24. The combination as set forth in claim 22 in which said mandrel further comprises key means acting between at least one of said cam surface means and its associated cylindrical segments to rotatably couple said cylindrical segments to said shaft means for simultaneous rotation therewith, and as said shaft means is relatively moved axially toward said support means said first and second cam surface means are moved toward each other to engage and cam said cylindrical segments to provide said radial movement thereof.

25. The combination as set forth in claim 24 is which, said urging means comprises a compression spring acting between said rod means and said shaft means, said compression spring being supported within an axial bore in the terminal end of said rod means, and said driven means comprises a driven shaft of noncircular cross section and comprising the terminal outer end of said shaft means, said driven shaft being adapted to be driven by compression clutch means comprising said drive means.

26. The combination as set forth in claim 25 in which said compression clutch means comprises an axially telescoping collet chuck yieldingly urged outwardly to an extended position and having a noncircular axial bore provided in its outer end portion which is adapted to receive the terminal end portion of said driven shaft therewithin to enable driving thereof.

References Cited UNITED STATES PATENTS 1,466,121 8/1923 Dallas 24272.1 1,710,902 4/1929 Stachowski 24272.1 2,483,528 10/1949 Christoff 24268.3 3,201,058 8/1965 Waldherr et al. 24272.1

NATHAN L. MINTZ, Primary Examiner. 

